Yarn tensioning apparatus



Nov. s, 196s YARN TENS IONING APPARATUS Filed May 26, 1966 ATTORNEYS United States Patent O 3,409,194 YARN TENSIONING APPARATUS Louie H. Whitehead, Aiken, S.C., assignor to Owens- Corning Fiberglas Corporation, a corporation of Delaware Filed May 26, 1966, Ser. No. 553,247 Claims. (Cl. 226-3) ABSTRACT 0F THE DISCLOSURE A method for handling alignment of yarn advancing through a tensioning device including a squeezing zone of opposing members wherein the yarn advances with the members urged together followed by a subsequent interval during which the members are not urged together and the alignment of the yarn occurs and finally re-establishing the urged together relationship of the members with the yarn aligned between them.

The word yarn as used in the present application includes strands, rovings, yarns, cords or any linear body. There are many instances in textile operations involving traveling yarn where applying controlled tension simultaneously to a great number of yarns in an effective and reliable manner is essential. An example is beaming of warp yarns where a plurality of yarns supplied from individual serving packages mounted on a reel are pulled through suitable individual yarn tensioning devices onto a driven warp beam. Satisfactory beaming occurs only when each yarn has substantially identical tension continuously applied to it by its individual yarn tensioning device. Uneven tensioning ofthe yarns results in nonuniformly wound warping beams providing yarns of varying length on the same warp beam and dissimilar yarn loop tension between yarns on the beam. These conditions cannot be tolerated in subsequent yarn processing such as weaving.

While not all yarn tensioning devices are equally effective in providing even tension between a plurality of yarns being pulled to a collection package (e.g. warping beam), prior art squeeze-type devices have demonstrated their usefulness. Prior art squeeze-type tension devices usually comprise two independent members or discs rotatably mounted on a post. The yarn enters between the discs along an entrance path and turns on the post to exit the discs along a different path, generally from 45- 135 degrees from its entrance path. Usually controlled tension is applied to the yarn through urging the discs together by weights, springs or electromagnetic force. Tension on the traveling yarn may be varied by changing the magnitude of the force urging the discs together. Further, once the yarns are threaded in proper alignment through the discs, continual disc pressure must be maintained, especially where there are long -lengths of unsupported yarn such as in the beaming of warp yarns. If a positive squeeze is not maintained on the yarn by the yarn tensioning device, the weight of the yarn gives rise to yarn run-out from the serving packages which brings about undesirable slack in the yarn.

Because squeeze-type yarn tensioning devices, in particular electromagnetically operated squeeze-type yarn tensioning devices, often permit yarn to escape from between their discs during normal yarn processing, the full advantage of their use has not been possible in the beaming of warp yarns and other textile operations. Since there may be as high as 700-800 yarn ends requiring equal individual tensioning from serving packages on a single creel during beam, escaping yarn becomes a serious problem. Escaped yarn permits undesirable nonuniform yarn tensioning and frequently makes possible yarn entanglement with the apparatus on the creel to cause the yarn to break.

3,409,194 Patented Nov. 5, 1968 Re-creeling is repeatedly required to return the yarn to operating alignment between the discs. Under such recreeling conditions an economical process is difficult to obtain.

An object of the invention is to provide a method and apparatus for tensioning a plurality of yarns with squeeze-type yarn tensioning devices which is substantially free from process interruptions caused by loss of yarn operating alignment with the devices.

Another object of the invention is to provide a method and apparatus for tensioning yarn which permits yarn t0 regain operating alignment with its squeeze-type yarn tensioning device when misalignment has occurred.

These and other objects are attained by interrupting the force urging together the members or discs of squeezetype yarn tensioning devices at a predetermined time for a selected time interval while the yarn is traveling. During the time interval the discs are not urged together. The traveling yarn which has escaped from between the discs or somehow has become misaligned is permitted to move into proper alignment between the discs because the discs are not squeezed together. The force urging the discs t0- gether is re-established at the end of the selected time interval to maintain proper yarn alignment and yarn tension.

Other objects and advantages of the invention will become apparent as the invention is hereinafter described in more detail with reference made to the accompanying drawings in which:

FIGURE 1 is a schematic representation of yarn handling apparatus comprising a beaming machine, a creel including electromagnetically operated yarn tensioning units and an electrical delay device embodying the principles of the invention.

FIGURE 2 is a cross-sectional view of a squeeze-type yarn tensioning device employed with the yarn handling apparatus shown in FIGURE 1.

FIGURE 3 is a diagram of an electrical circuit -for the delay shown in FIGURE 1 embodying the principles of the present invention. l

Referring now in detail to the drawings, FIGURE 1 illustrates an example of a textile beaming operation incorporating electromagnetically operated squeeze-type yarn tensioning devices and employing a delay device embodying the principles of the present invention. A conventional beaming machine 10 draws a plurality of yarns 12 from a standard textile creel 14 onto a warp reel 16 which is rotated through suitable drive apparatus by a motor 18.

The creel 14 is a frame supporting a plurality of bobbins or serving packages 20 which provide the yarns 12 which are wound in side by side relationship on the warp reel 16. The creel 14 may be large enough to support hundreds of serving packages and may be 70-80 feet away from the beaming machine 10. Associated with each serving package 20 is an electromagnetically operated squeeze-type yarn tensioning device 22. The yarn 12 drawn from each serving package 20 proceeds through its associated tensioning device 22 on the yarns way to the warp reel 16.

Electrical current to the motor 18 is supplied from a suitable electrical source 24, e.g. 220 volt AC, through leads 26 and 28. Electrical power to the motor 18 is controlled by the beamer switch 30.

A delay device 32 is connected in parallel across the electrical power leads to the motor 18, leads 26 and 28, by leads 34 and 36 positioned between the beamer switch 30 and the motor 18. Operation of the delay device 32 is controlled simultaneously with the operation of the motor 18 by opening and closing the beamer switch 30.

Electrical current is supplied to the electromagnetically operated squeeze-type yarn tensioning units 22 from a suitable electrical source 38 through leads 40 and 42.

Delay device 22 is electrically interposed between the electrical source 38 and the yarn tensioning devices 22 along leads 40 and 42.

FIGURE 2 shows, by way of example, an electromagnetically operated squeeze-type yarn tensioning device 22 capable of 4being employed in the process illustrated in FIGURE l. The yarn tensioning unit 22 includes a post 52, a coil 54 and `annular discs 56 and 58 and is mounted on a support plate 60.

The coil 54 is wound on a tubular member 62 made of nonmagnetic material, eg. nylon, and having an inside diameter which allows the member 62 to slide down over the post 52. The coil 54 is held in a cylindrical container 64 open at the upper end and having a circular bottom 66 and a tubular wall 68 extending upwardly generally the height of coil S4. The bottom 66 has an opening through it positioned at its center.

The container 64 is securely positioned on support plate 60 by the upstanding post 52, which comprises a sleeve 70 and a bolt 72. The bolt 72 extends through the length of the ysleeve 70, and further, the threaded end of the bolt 72 extends through the center opening in the bottom 66 and a matched opening in the plate 60. A nut 74 is screwed on the threaded end of the bolt tightly against the bottom of the plate 60.

Annular discs 56 and 58 -are freely rotatably mounted on post 52. The lower annular disc 58 rests on tubular wall 68 across the upper end of the container 64 and has an outwardly and downwardly extending rim portion extending beyond the outside diameter of the container 64. The disc 58 is usually fabricated of a non-magnetic material. The upper annular disc 56 is disposed on top of disc 58 and in the embodiment illustrated if FIGURE 2 is somewhat smaller in diameter. The disc 58 has an outwardly and upwardly extending rim portion, which when paired with the flat surface of disc 56 forms a circular furrow, within which a yarn which has escaped from between the discs may ride. Disc 56 is made of magnetic material, e.g. steel.

The operation of an electromagnetically operated squeeze-type yarn tensioning device is well known. When the coil 54 is energized by current supplied from the electrical source 38, the resulting magnetic lines of force emitted from the coil 54 pass through a path comprising the upper annular disc 56 and provide a force tending to draw the disc 56 towards the coil 54. The force further urges the upper annular disc 56 towards the lower annular disc 58; hence, when the coil 54 is energized, the discs are urged together into a frictional engagement with the yarn 12 when the yarn 12 is proceeding in proper alignment between them. The amount of pressure and thereby the amount of tension applied to the yarn 12 depends upon the force urging the discs 58 and 56 together 'and may be varied by regulating the amount of current supplied to the coil 54.

In operation the yarn 12 is drawn from the serving package along a path running between the discs S6 and 58 0f yarn tensioning devices 22. The path the yarn takes while between the discs may be straight or bent by turning the yarn 12 on the post 52. If the yarn 12 is turned on the post 52, the exit path of the yarn is in a direction different from its entrance path to the discs from serving package 20. While in practice the yarn 12 is bent one-quarter of a turn on the post 52, the turn may be greatly varied. In any case the principles of the present invention are applicable.

FIGURE 3 illustrates an example of an electrical circtit for the delay device 22 which embodies the principles of the present invention. The circuit comprises control coils or electromagnets 94, 98, and 102 and their associated spring biased armatures 96, 100, and 104 respectively and pneumatic timing unit switches 106 and 108.

When energized the circuit operates as a relay to open pneumatic timing unit switch 110 at a predetermined time after beamer machine start-up. The switch 110 is located in the lead 42 supplying electrical current to the coil 54 of the tension units 22, opening the switch 110 interrupts electrical current to the coils 54.

As shown in FIGURE 3, the electrical source 24, also supplying current to the beaming machine 10 through leads 26 and 28 as described hereinabove, supplies electrical current to the leads 34 and 36. While the armature 96 is pressed by the compression spring 97 to maintain the pneumatic timing unit switch 106 open, a solenoid force established by current flowing through the control coil 94 pulls the armature 96 to the control coil 94 and away from the switch 106, freeing the pneumatic timing unit switch 106 so that it may operate. The switch is set to close at a predetermined time after withdrawal of the armature 96 by means of suitable pneumatic apparatus (not shown) well known in the art. When pneumatic timing unit switch 106 closes, coil 98 is immediately energized, establishing lines of force which pull the armature 100 away from the pneumatic timing unit switch 108, which is maintained closed by the armature 100 positioned by compression spring 101 and timed to open by appropriate pneumatic apparatus (not shown) when the switch 108 is freed. In the case of switch 108, it is closed only long enough to permit the control coil 102 to become energized, pulling the armature 104 to itself by solenoid force. Here, however, the armature 104 and the coil 102 are in reverse position with respect to the armatures 96 and 100 and their respective control coils. When the coil 102 is energized, the armature 104 is thrust to open the normaly closed switch 110. Because switch 108 is closed only momentarily, the control coil 102 is only transitorily energized. While the armature 104 moves under the solenoid force of the energized control coil 102 to open switch 110, it is immediately returned to its initial position out of contact with the switch by tension spring 105. The switch 110 is timed to close at a selected time after opening by appropriate pneumatic apparatus (not shown).

While switch 110 is open, all electrical current to the coils 54 of yarn tensioning devices 22 is stopped. Yarn continues to travel to the beamer reel 16 illustrated in FIGURE l; however, the tensioning discs 56 and 58 are free from any electromagnetic force urging them t0- gether. After the selected time interval, pneumatic timing unit switch 10 closes to re-establish electrical current to the coils 54. Because pneumatic timing unit switch 108 is initially closed, current passes almost instantaneously to the coil 102 after pneumatic timing unit switch 106 is closed, and consequently the period of time which the pneumatic timing unit switch 106 is open after beamer machine start-up is essentially the delay period after the start-up of beaming machine 10 before electrical current to the coils 54 is interrupted. After the pulse of current to the coil 102, the switch 108 is opened and the coil 102 is de-energized and the armature 104 is swiftly returned to its initial position by tension spring 105. The time interval for closing switch 106 may be changed by adjusting the pneumatic timing apparatus to suit the machinery and process employed. In practice 7-8 seconds has been found an adequate delay before closing switch 106 when conventional beamer machines are employed. This delay allows the beamer machine to attain a predetermined desired speed.

While in practice 7-8 seconds after start-up of a beamer machine has been found adequate before interrupting current to the coils of electromagnetically Operated yarn tensioning devices, this time may be varied. The important thing is that the yarn be traveling so that the yarn will pull itself back between the discs when they (the discs) are in a relaxed or non-urged together condition. Machinery which hastens the yarn to speed requires less delay after process start-up before electrical current to the coils of the yarn tensioning devices 22 is interrupted.

In practice 3-4 seconds has been found adequate time to permit the yarn 12, which has escaped from between the yarn tension discs 56 and 58, to be captured in proper operating alignment between the discs. Thus, in practice switch 110 is timed to close 3-4 seconds after being opened. This time may be Varied.

While an electromagnetically operated yarn tensioning devices have been illustrated, the principles of the present application are applicable to handling of traveling yarn where any squeeze-type yarn tensioning device, e.g. spring or weight biased discs, is employed.

It can be seen that the invention described provides as effective method for handling a plurality of traveling yarns in textile operations Where squeeze-type yarn tensioning devices are employed which is substantially free from interruptions cause by the yarn losing operating alignment from between the members or discs of the tensioning devices.

In view of the foregoing it will be recognized that while a particular example of a delay arrangement providing a predetermined interruption of electrical power to the coils of electromagnectically operated yarn tensioning device for a selected time interval has been made many modications thereto, in addition to other arrangements, may be employed to gain the same predetermined interruption of the force urging together the discs of squeeze-type yarn tensioning devices for a selected time interval and, therefore, it is not the intent to limit the invention to specific embodiments.

I claim:

1. A method for handling alignment of traveling yarn advanced from a source through a squeezing zone including opposing members from which said yarn has become misaligned comprising the steps of advancing said yarn from rest while a force is applied urging said members together,

releasing said force for a time so that said members are not urged together, said advancing yarn realigining itself between said members during interruption of said force, and

applying said force again to urge said members together, said yarn continuing to advance without interruption.

2. In a textile operation where yarn is tensioned by advancing said yarn between a pair of members capable of being urged together, a method for handling alignment of said traveling yarn comprising the steps of advancing said yarn from rest to a predetermined speed while a force is applied to said members urging said members together,

interrupting said force for a time to said members when said yarn reaches said predetermined speed so that said members are not urged together, said yarn when out of alignment becoming realigned during 5 said time, and

re-establishing said force to said members after said time to again establish the desired tension in said yarn.

3. In a textile beaming operation where a plurality of yarns are tensioned by advancing each of said yarns between a pair of rotatably mounted discs capable of being urged together, a method of handling alignment of said traveling yarn comprising the steps of advancing said yarn from rest While a force is applied to said discs urging said discs together,

interrupting said force for a period to said discs at a predetermined time after commencement of yarn travel so that said discs are not urged together, said yarn when out of alignment between said discs during the interruption of said force pulling itself into alignment between said discs, and

re-establishing said force to said discs after the interruption to again establish the desired tension in said yarn.

4. A method of handling traveling yarn recited in claim 3 where said torce applied to said discs 'is electromagnetic.

5. In a textile beaming operation where yarn is tensioned by advancing said yarn along a path running between a pair of discs rotatably mounted on a post and said yarn is turned on said post to leave said discs at a different path from its path of entrance, a method of handling alignment of said traveling yarn comprising 35 steps of advancing said yarn from rest -to a predetermined speed with a force applied to said discs urging said discs together,

interrupting said force for a time to said discs so that said discs are not urged together, said yarn when out of alignment between said discs during the interruption of said force pulling itself into alignment between said discs, and

re-establishing said force to said discs yafter said time to again establish the desired tension in said yarn. 

